1. Field of the Invention
The present invention relates to a compensation method for structural deformation, and more particularly, to a compensation method for structural deformation occurring during construction of a super tall building.
2. Background of the Related Art
A structure of a building may deform during the construction of the building according to the physical features (e.g., modulus of elasticity, creep, drying shrinkage, and so on) of the materials thereof. Since the deformation of the structure cumulatively increases in proportion to the number of floors of the building, it may occur a lot vertically and horizontally on the upper floors of the super tall building.
Especially, the deformation of the structure occurring during the construction of the super tall building causes the structural performance of the structure to be deteriorated badly and further causes troubles in the performance and construction processes of finishing, mechanical and plumbing (e.g., curtain walls, elevators, floors, partitions, windows, vertical pipes, horizontal pipes, and so on).
Accordingly, a compensation method for the deformation of the structure has been developed and applied at a construction site. In this case, the deformation of the structure is predicted before the construction of the building, and next, during the construction of the structure, the compensation for the structural deformation is carried out to a direction opposite to the direction where the deformation of the structure occurs.
According to the conventional practices, the amount of compensation for the structural deformation is calculated on a basis of a prediction value for structural deformation, and the prediction value is obtained on a basis of specific time called a target date. Generally, the target date becomes the date on which construction is completed or the date after which a period of time is passed after the completion of the construction. That is, the amount of deformation occurring on each floor of the building on the target date is applied to a direction opposite to the direction where the deformation occurs, which becomes theoretical amount of deformation.
FIGS. 1 and 2 are schematic views showing compensation method for structural deformation occurring during construction of a specific level of a super tall building in a conventional practice. As shown in FIG. 1, if no compensation for the structural deformation is carried out, on a basis of the target date on which construction is completed, the amount of shortening x0+y0 of an exterior column C2 may become larger by y0 than the amount of shortening x0 of an interior core C1. In FIGS. 1 and 2, DL means design level, CL construction level, and FL final level after deformation. That is, it is found that a difference between the DL and FL is made.
So as to perform the compensation for the difference, as shown in FIG. 2, the exterior column C2 is constructed higher by the amount of shortening x0+y0 and the interior core C1 is constructed higher by the amount of shortening x0 on the basis of the target date on which construction is completed. As a result, a theoretical difference between the DL and FL is not made after the structural deformation occurs.
As well known, the compensation for the structural deformation on the basis of the time on which the construction is completed is divided into a compensation method for all of the deformation occurring on the respective portions of the building (total deformation) and compensation method for only deformation occurring by a difference between a specific portion of the building and a portion adjacent to the specific portion (relative deformation or differential deformation).
FIG. 3 is a flow chart showing an algorithm of a prediction method for axial shortening in a super tall building according to a conventional practice. As shown in FIG. 3, according to the conventional practice, if the super tall building has n floor slabs, the conventional prediction method includes the steps of calculating the amount of shortening before casting and the amount of shortening subsequent to casting on a basis of the slab casting time for each floor (i-th floors). The conventional compensation method determines the amount of compensation for the structural deformation in accordance with the amount of shortening before casting and the amount of shortening subsequent to casting obtained from the above step.
However, the conventional compensation method for the structural deformation does not provide any improvement in the decrease of the structural performance of the structure. Even if the compensation for the structural deformation is carried out on the basis of the construction completion time, the structural deformation still occurs during the construction, and therefore, stress developed in the structure due to differential deformation does not disappear.
Moreover, the conventional compensation method for the structural deformation does not remove the troubles occurring in construction processes of finishing, mechanical and plumbing. The construction processes of finishing, mechanical and plumbing are performed a little later after the construction of the structure, and generally, they are carried out on a state where their plumb and levelness are adjusted separately from the plumb and levelness of the structure. Otherwise, the processes are carried out by using self-leveling materials.
However since the amount of compensation for the structural deformation in the conventional compensation method is calculated on the basis of the target date on which the construction is completed, the plumb and levelness adjusted during the construction processes of finishing, mechanical and plumbing are misaligned to a direction opposite thereto, thereby causing the same problems as when no compensation for the structural deformation is performed.
Furthermore, since the conventional compensation for the structural deformation is limited only to the deformation of vertical members, it is not adequate for the complex structural deformation of a super tall building having an asymmetric structure.